Why do evil scientists build their secret lairs in volcano islands?

A volcano island offers many advantages to the enterprising evil scientist:

Land near the volcano is cheap, land on the volcano is even cheaper, and land inside the volcano is practically free!

If the island is far enough from other land, you can use it as a base to launch rockets or intercontinental missiles without endangering or causing inconvenience to any surrounding population.

Lots of geothermal energy provide heating in Winter and allow you to power a great amount of equipment without spending a single euro and without emitting any CO2 to the atmosphere. It is Green energy!

If you ever need to deliver a nuclear warhead or a Laser pulse to the Earth's core, easy access to a magma chamber provides a convenient pathway for a drill.

If you are artistically inclined, the volcano presents a big face of rock on which you can carve your face, a skull with glowing eyes, or anything you want.

Of course, it also has its disadvantages:

Its distance to land will mean that you'll need to ferry any materials by helicopter, plane or boat, which can become expensive very soon.

This also means that you'll need to provide transportation, lodging, food and entertainment to all your minions.

Finally, take into account that, even though you have the whole island to yourself, this island still belongs to a country, so you may not be exempt from its employment laws and labor agreements. Many forget this, and then get in lots of trouble and have to pay millions in compensation when a secret agent comes and wrecks the place and hundreds of minions die.

Jacobo Tarrío is not an evil scientist, but spends too much time thinking about how to get an island, declare independence, and then rule it with an iron fist.